The present invention relates to a stitchless seam system between laminates which results in a functionally liquid-proof stitchless seam width created between adjacent panels of laminates. The stitchless seam system is of use in the construction of high performance waterproof apparel and footwear. While traditional fused seams are useful in liquid proof garments, such seams tend to be rather stiff. Further, the continual flexing of the stitchless seam leads to a reduced lifespan of the garment. The stitchless seam of the present invention allows the formation of seams of very small dimension which provide flexibility and retain the integrity of the seam to prevent cracking. The use of coated textile composites or laminates of textiles and liquid protective barrier membrane layers to create liquid-proof protective apparel and protective footwear is known in the industry. The most common of these applications is waterproof breathable apparel. Typical examples are laminate materials sold by W.L. Gore and Associates, Inc. under the registered trade name GORE-TEX, which contain a waterproof breathable film laminated, or bonded, to one or more textile layers. These laminates are fabricated into apparel and footwear and sold as GORE-TEX® garments and the like. Coated textiles can also be used in textile composites for these same purposes.
Pieces or panels of these laminates are joined together to form garments and other similar textile structures. In the case of footwear, pieces or panels of laminates are typically joined together to form booties which are then integrated as a liner in the shell of the footwear and combined with the sole. For the garments and footwear to be liquid proof and protective, there is a need to seal the seams where the panels of laminate are joined together. The joining of these laminate panels is typically done by first sewing the laminates together using conventional sewing techniques. Liquid-proof sealing of these sewn seams is then accomplished by the application of a seam seal tape having a thermoplastic hot-melt adhesive which seals to the surface of the coating or protective barrier film and creates a seal over the sewing holes and the area where the layers join between the stitches. The seam seal tape may be heated, for example, using a nozzle to direct a stream of hot air so as to melt the adhesive. The tape is then applied over the seam and both are passed through the nip of a pair of pressure rollers in order to squeeze the molten adhesive onto the protective layer surface to ensure good bonding of the tape to the surface. For aesthetic reasons, the seam sealing tape is generally applied to the interior of a garment so that it is hidden from view. In the case of a bootie for covering the foot, the seam sealing tape is generally applied to the exterior of a bootie which is between the lining material and the shell of the footwear so that it is hidden from view. Less common sealing techniques such as gluing and fusing are also known in the art.
Different fused seams have been disclosed in the art, but none of the prior art teaches the present invention. U.S. Pat. No. 6,797,088 discloses a method for connection of pieces of textile fabric. In this method, a cut edge is formed and the threads bound at the cut edge of each of the textile pieces. The textile pieces are then laid on each other in an overlapping manner and the pieces are pressed together between a sonotrode and an anvil. At least one of the sonotrode or anvil has a surface profile with a number of elevations. The textile pieces are connected by ultrasonic oscillation of the sonotrode. The pattern of elevations in the sonotrode and/or anvil results in fusion or plasticization of the textile pieces at particular points only while leaving textile fabric at other points. Thus, a discontinuous ultrasonically fused seam is produced.
U.S. Pat. No. 6,103,325 discloses an ultrasonically formed seam comprising a laminate sheet constructed solely of a polyester fabric on one side and a polyurethane coating on the other side of the sheet. To form the seam, sides of the fabric coated with polyurethane are brought into contact and ultrasonic energy is applied to fuse the fabrics together to form a unitary, monolithic fluid-proof seam;
Publication No. WO2005/000055 discloses a fused seam between the edges of two laminates wherein each textile layer is made up of two components with different melting temperatures. The seam is formed by the melted second component and the non-melted first component of the textile layers of each laminate. Edges of the seamed laminates are in an edge-to-edge butt orientation.
Publication No. US2003/0135185 discloses adhesiveless absorbent garments, the components of which are held together by one or more adhesiveless bonds. In one embodiment, the adhesiveless bonds are formed ultrasonically.
A need exists in the garment and footwear industry for a reliable and effective technique for joining two or more panels of a complex or multi-layered textile laminate construction to form a flexible liquid-proof seam in garments and protective footwear. There is a further need in the industry for a liquid-proof fused seam which exhibits flexibility, durability, strength, and crack resistance. The present invention solves the need of the industry.